<template>
  <div class="todo-footer">
        <label>
          <input type="checkbox"  v-model="addAll"/>
        </label>
        <span>
          <span>已完成{{isSize}}</span> / 全部{{todos.length}}
        </span>
        <button class="btn btn-danger" v-if="isSize>0" @click="$bus.$emit('deleteTodos')">清除已完成任务</button>
      </div>
</template>

<script>
export default {
    name:'Footer',
    props:{
      todos:Array,
    },
    computed: {
      isSize(){
        return this.todos.reduce((pre,item)=>pre+(item.done?1:0),0)
      },
      addAll:{
        get(){
          return this.isSize === this.todos.length && this.isSize > 0
        },
        set(val){
          this.$bus.$emit('checkadd',val)
        }
      }
    },
}
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>